Not over preparing for class each day but focusing more on finals makes sense. Review for previous material and study it once you go over it in class because then you have a foundation. Like he says, you aren't graded on lecture, so why prepare yourself too much for class? Fear? If you cap your studying you are taking the big picture approach.

I don't see a big problem with "over preparing for class." If you are studying the material, and know the material, it will obviously help you later on when you start studying for the exam. My common mistakes:

-Not preparing for class (either not reading OR reading but not understanding the basic aspects of the reading);-Skipping class;-Procrastinating with papers (for legal writing) or studying/outlining;-Not listening during lectures (surfing the internet or something);-Not participating in class (this is based on the professor, but some do add points for class participation);-Not having a plan OR thinking about finding a job (either procrastinating on applying for jobs or doing a poor job networking OR searching for a job);-Taking out too many loans to attend law school.